Process for the preparation of alpha-nitro-isobutene



atented ept 4, 145

PROCESS FOR a-NlTRO-IS PREPATION F oau'rma Arthur Ernest Wilder Smith,Charles William Scaite, and Robert Holroyd Stanley, Nortonon-Tees,England. assignors to Imperial Chemical Industries Limited, acorporationof Great Britain No Drawing. Application December 15, 1943,Serial No. 514,1519. In Great Britain December 4,

1 Claim.

This invention relates -to the production of a-nitro-isobutene.

The compound known as 1,2-dinitro-2-methyl- I propane, also known asalpha, beta-dinitroisobutane, is well-known, being disclosed by Michaeland Carlson in the Journal of Organic Chemistry, volume 5, pages 1 to13, which reference disclosed the preparation of this compound as theprincipal product in the reaction of anhydrous nitrogen tetroxide withisobutylene. These authors refer also to Ssidorenko (Chem. Zentralblatt1907, I, page 399) who found that "nitrogen tetroxide acted uponisobutylene in ether solution to yield as the main product a blueliquid. which gave a low yield of isobutylenediamine on reduction.

According to the present invention cz-IiltiO-ISO- butene is prepared byreacting dinitro-isobutane with an aliphatic alcohol, the reactionapparently proceeding according to the equation:

(CI-Ia) 2C.NO2CH2NO2+ROH- (CHsizCZCHNOz-l-RONO-i-HaO where ROHrepresents the alcohol.

Naturally the dinitro-isobutane referred to is 1,2-dinitro-isobutane,since it is not indeed possible to prepare the a-nitro olefinefrom anyof the other compounds.

The temperature does not appear to be critical. At room temperature andbelow the reaction is slow, but, it increases rapidly as the temperatureis increased. In general, temperatures between C. and C. are suitable.

, Example 30 grams of dlnitro-isobutane were dissolved in 200 cos. ofmethylated spirits and refluxed for 16 hours. The excess alcohol wasthen removed by distillation, when a residue consisting of an aqueousphase and a lachrymatory yellow oil was obtained. To the residue wasadded twice its

